Decorative laminates have been used as surfacing material for many years, in both commercial and residential applications. Decorative laminates can provide an aesthetically pleasing surface that is more economical and/or has improved physical characteristics compared to similar looking alternatives. For example, decorative laminates can be used to create flooring that has the appearance of real hardwood flooring but is less expensive and more durable than real hardwood flooring.
In addition to flooring, decorative laminates are often used in furniture, countertops, cabinets, wall paneling, partitions, fixtures, and the like. As described above, decorative laminates can be made to resemble real wood. Decorative laminates can also be made to resemble such other materials and surfaces as stone, ceramic, marble, concrete, leather, fabric, brick, tile, and the like. In other applications, instead of being made to resemble a particular traditional material or surface, a decorative laminate may be made to provide more fanciful surfaces.
More recently, decorative laminates have been improved to include a three-dimensional “textured” surface. In this way, decorative laminates can be made to not only look like some other material or surface, but can also can be made to feel like the other material or surface. In fact, decorative laminates can be made to so closely resemble the look and feel of other materials that one cannot easily determine whether the surface includes the real materials or is a faux representation of the real materials. For example, a textured decorative laminate made to look like real wood paneling may include a plurality of depressions and/or protrusions on its surface to create a texture that simulates the grains and knots of real wood boards. In another example, the textured decorative laminate may be made to look like a plurality of ceramic tiles separated by grout lines. In such an embodiment, the surface of the laminate may be made so that the images of the grout lines are depressed relative to the images of the ceramic tiles. In still other applications, textured decorative laminates may be made with more fanciful visual artwork and may have embossing and textures that work in conjunction with the visual artwork to create a more interesting and aesthetically pleasing surface.
In general, decorative laminates are classified into two broad categories based on how the laminates are manufactured, namely “high” pressure decorative laminates (HPDLs) and “low” pressure decorative laminates (LPDLs). In general, the industry considers “high” pressure decorative laminates as those laminates that are manufactured or “laminated” under a pressure of generally more than 750 psig. “Low” pressure decorative laminates are typically manufactured at a pressure of about 300 to 600 psig.
HPDLs and LPDLs are often further distinguished by the fact that HPDLs are typically manufactured by first laminating a decorative paper layer with one or more other thin layers and a resin to create a relatively thin and flexible laminate. This thin and flexible laminate is then typically adhered to a thicker, self-supporting substrate layer during a later stage of manufacturing. In contrast, LPDLs are typically manufactured by laminating the decorative paper layer with the self-supporting substrate layer, such as particleboard or MDF, and a resin in a single laminating or “pressing” operation. Generally, the idea is that the higher pressures involved in manufacturing HPDLs will crush the substrate layer beyond that which may be desirable. For this reason, LPDLs are sometimes also referred to as “direct” pressure decorative laminates (DPLDs) since the decorative layer is laminated or “pressed” directly onto the substrate layer in a single step. However, it should be noted that, although manufacturing HPDLs typically involves the two steps described above while manufacturing LPDLs typically involves the one step described above, this is merely a generalization about the typical manufacturing processes used to make the two different types of laminates. In some procedures, an HPDL may be laminated with a self-supporting substrate layer in a single pressing step and a LPDL may be adhered to a substrate layer in more then one step.
FIG. 1 illustrates an exemplary LPDL 5 and press system 1, such as one that may be used in accordance with embodiments of the present invention. As illustrated in FIG. 1, the laminate 5 generally comprises a decorative layer 6 and a substrate layer 8. The decorative layer 6 is typically a sheet of paper or similar material having a decorative image or pattern printed thereon. The substrate layer 8 is used to provide structure to the laminate 5 and may comprise, for example, particleboard, high-density fiberboard (HDF), medium-density fiberboard (MDF), or the like. The decorative layer 6 is soaked or otherwise coated with resin, such as a thermosetting melamine formaldehyde resin, and is bonded to the substrate layer 8. In some embodiments, one or more other layers are bonded with the decorative layer 6 and the substrate layer 8. For example, a substantially transparent wear-resistant layer 12 may be bonded over top of the decorative layer 6 to protect the “top” surface of the final laminate. Likewise, a base layer 10 may be bonded to the lower surface of the substrate to protect the “bottom” surface of the final laminate.
As illustrated in FIG. 1, these layers are at least partially coated or saturated with resin and are placed in a press 2 where they are bonded together under heat and pressure. For example, the layers are typically heated to approximately 160 to 220 degrees Celsius and pressed together at approximately 300 to 400 psi for approximately 15 to 20 seconds. The heat cures the thermosetting resin, thereby bonding the layers together. For textured decorative laminates, the upper portion of the press 2 typically has a press plate 4 attached thereto, where the press plate 4 has a plurality of depressions and/or protrusions arranged in a three-dimensional design. When the press plate 4 is pressed into the resin and against the upper surface of the laminate, the resin on the upper surface cures with an imprint of the three-dimensional surface of the press plate therein. The press 2 may also include a lower press plate 3 attached thereto. The lower press plate 3 may have a flat, smooth surface or, in some embodiments, may have a plurality of depressions and/or protrusions arranged in a three-dimensional design so that the lower surface of the laminate is embossed in addition to or as an alternative to the upper surface of the laminate.
Importantly, the textured press plate 4 must be aligned precisely with the decorative layer 6 so that the texture design pressed into the laminate is properly aligned with the decorative image or pattern on the decorative layer 6. If the press plate 4 is even slightly out of register with the decorative layer 6, the resulting laminate may have to be discarded. For example, if the texture pattern is slightly shifted or angled relative to the decorative pattern, a moiré effect can be created resulting in a significantly blurred image or the appearance of undesirable patterns in the laminate. In another example, a feature of the texture design is obviously misaligned with some corresponding feature of the decorative image. For instance, where the decorative image is of a tiled surface, a ridge that is intended to be aligned with the edge of a tile in the decorative image may instead fall in the grout line area or the tile area of the decorative image.
The registration of the press plate and the decorative layer is further complicated by the fact that the metallic press plate expands when heated during the laminating process and the fact that the decorative layer and the substrate layer may also expand based on the specific material properties of each layer. Furthermore, each press may uniquely effect how a press plate will grow based on how the particular press fixes the press plate to the press, e.g., based on the position and spacing of lugs and/or clamps used to secure the press plate to the press.
A system for generating HPDLs may, in some cases, be similar to the LPDL system shown in FIG. 1. The pressures and temperatures, however, will generally be significantly higher in an HPDL system compared to an LPDL system. Although the layering in an HPDL may be different than that of a typical LPDL system, the manufacture of textured HPDLs still generally involves use of a press, a textured press plate, a decorative layer, and a thermosetting polymeric resin.
Typically, the party that manufactures the laminate has another party create the textured press plate(s) used in the manufacturing process. Since press plates must be able to withstand significant and repetitive heat and pressure changes and since press plates must typically have very detailed and precise texture patterns formed of many minuscule depressions and/or ridges in the press plate, the manufacturer of the press plate is typically a company that specializes in the manufacture of precision metal plates. Although the laminate maker, and perhaps the end user of the laminate, generally decide on what will be a suitable texture for the resulting laminate, the press plate manufacturer is also usually involved in the design of the texture since the press plate company typically has significant knowledge of which textures are possible and at what cost different textures can be made. As such, the laminate designer typically must work closely with the press plate manufacturer in order to obtain the desired look and feel of the finished laminate and to determine allowable tolerances in the registration of the press plate and the decorative layer.
Since the design process is usually an iterative one, there needs to be fast and economical ways for the different parties involved in the design process to communicate ideas to one another and to determine how the finished product will appear without having to make full scale press plates and laminates each time a change is made or another idea is tried during the laminate design process.